Inspection and Reconditioning (Rev 1/97)
46
Measuring Main Journal
NOTE: The most accurate method of determining the
outside diameter of the undersized main journals is to
install the main bearing caps with the undersized
bearing inserts in place. Properly torque the main
bearing caps to the block and measure the inside
diameter of the main bearings. Subtracting the sug-
gested oil clearance (refer to Specifications) from the
inside diameter of the main bearings results in the
correct outside diameter for the undersized main jour-
nals.
3. Measure the rod journals. If any of the rod journals are
smaller than the wear limits, (refer to Specifications) or
tapered or out of round more than .0010 in. (0.025
mm), the rod journals must be ground undersize.
Measuring Rod Journal
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Only the .010 in. (0.25 mm) undersize rod bearings are
available. Refer to Specifications for the suggested out-
side diameter of undersized rod journals.
NOTE: The most accurate method of determining the
outside diameter of the undersized rod journals is to
install the rod caps with the undersized bearing
inserts in place. Properly torque the rod caps to the
rods and measure the inside diameter of the rod bear-
ings. Subtracting the suggested oil clearance (refer to
Specifications) from the inside diameter of the rod
bearings results in the correct outside diameter for the
undersized rod journals.
4. Measure the crankshaft deflection by placing the front
and rear main journals in a set of “V” blocks, or place
the crankshaft in the block resting on only the old front
and rear upper main bearing inserts. Set a dial indicator
on a middle main journal and rotate the crankshaft one
full turn. The crankshaft deflection equals one half of
the largest difference in readings on the dial indicator.
If the crankshaft deflection is greater than .0008 in.
(0.020 mm) the crankshaft must be replaced.
Measuring Crankshaft Deflection
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